Australia’s building codes are crucial for protecting people, including limiting window openings in multi-storey buildings to 125mm to prevent falls. Yet this essential safety measure can create an unintended consequence in reduced natural ventilation.
Research commissioned by Amplimesh and conducted by Western Sydney University and the University of Technology Sydney shows that restricted airflow can significantly affect indoor comfort and overall occupant wellbeing.
The independent study, The Role of Ventilation in Occupant Wellbeing, found that limited window openings in student housing led to higher carbon dioxide (COâ‚‚) levels, poorer airflow and reduced comfort. ASHRAE, a global authority on building ventilation, identifies 1,000ppm of indoor COâ‚‚ as an acceptable benchmark for bedrooms.
In the study, rooms with restricted windows consistently approached this upper limit, whereas fully opened windows delivered significantly healthier results. Greater ventilation correlated with improved occupant wellbeing, particularly in the mornings when outdoor air was cooler and fresher.
These findings build on prior research showing that many Australian schools are poorly ventilated. A 2019 study across ten Victorian schools found COâ‚‚ levels in classrooms frequently exceeded recommended standards and long-term monitoring in 2023 revealed that seven out of ten classrooms still fell below optimal ventilation levels.
Poor airflow has been linked to Sick Building Syndrome, which can cause headaches, fatigue and respiratory issues. The Australian Government’s Department of Health recognises that improved ventilation reduces the spread of respiratory diseases, a lesson reinforced during the COVID-19 pandemic.
The study underscores a key challenge for architects, facility managers, regulators and designers: How to balance vital safety measures with the need for healthier indoor environments. While limiting windows to 125mm helps prevent falls, it can compromise air quality in education campuses, student housing, aged care facilities and high-density apartments.
Researchers tested a practical solution by fitting one room with a protective screen supplied by Amplimesh. This allowed the window to open fully while still preventing falls. The screened room achieved consistent air change rates, unlike rooms with restricted openings. In colder weather, the screened room also retained warmth more effectively, demonstrating that improved ventilation can coexist with energy efficiency and comfort.
“Ventilation is not just about comfort, it’s about health,” Capral group manager of technology solutions Matthew Leishman says.
“Safe window design can provide fresh air, reduce reliance on mechanical systems and deliver better outcomes for occupants in schools, aged care facilities, and high-density housing.”
For building designers, policymakers and educational institutions, the research raises an important question: Do current building codes strike the right balance between safety and wellbeing, or is it time to rethink how Australians can breathe easier indoors?
